Iodoethyl esters of aromatic carboxylic acids

ABSTRACT

Halogenethyl esters of aromatic carboxylic acids are useful ingredients to influence plant metabolism. They may be used preferably for regulating fruit abscission.

United States Patent [191 Rohr [111 3,821,285 June 28, 1974 IODOETHYLESTERS OF AROMATIC CARBOXYLIC ACIDS [75] Inventor: Otto Rohr, Therwil,Switzerland [73] Assignee: Ciba-Geigy Corporation, Ardsley, N.Y.

[22] Filed: Mar. 29, 1972 [21] Appl. No.2 239,328

[30] Foreign Application Priority Data Apr. 1, 1971 Switzerland 4775/71[52] US. Cl 260/476 R, 71/69, 71/107,

260/469, 260/471, 260/473 G, 260/473 R [51] Int. Cl. C07c 69/78 [58]Field of Search 260/473 G, 476 R [56] References Cited UNITED STATESPATENTS 10/1921 Altwegg et al.. 260/476 R 3,256,305 '6/1966 Gijzen3,689,522 9 1972 Rossi ct al 260/476 R FOREIGN PATENTS OR APPLICATIONS28,247 10/1911 Great Britain 260/476 R 1,043,150 9/1966 Great Britain260/476 R 9/1959 Great Britain 260/476 OTHER PUBLICATIONS Beilsteins IHandbuch der Organischer Chemie, Vierte Auflage, Drittes Erganzungswerk,Vol. 9 pp. 388-389 (1970).

Beilsteins ll Handbuch der Organischer Chemie, Vierte Auflage, DrittesErganzungswerk, Vol. 9 p. 2178 (1970).

Primary Examiner-L0rraine A. Weinberger Assistant Examiner-Patrick J.Hagan Attorney, Agent, or Firm-Falba, Harry; Frederick H. Rabin [5 7ABSTRACT l-lalogenethyl esters of aromatic carboxylic acids are usefulingredients to influence plant metabolism. They may be used preferablyfor regulating fruitabscission.

2 Claims, No Drawings The present invention relates to a process for thecontrol of plant metabolism with the aid of halogenethyl esters ofaromatic carboxylic acids corresponding to the general formula l:

The symbols in this formula have the following meanmgs:

R, represents hydrogen, lower alkyl, lower alkoxy, lower halogenalkyl,nitro, halogen, or the group R,OCO- wherein R represents alkyl,halogenalkyl, substituted or unsubstituted phenyl,

R represents hydrogen, halogen, lower alkoxy, lower alkyl,

R represents hydrogen. lower alkoxy,

A represents the methylene group, the 'vinylene group (CH=CH-) or loweroxyalkylene,

X represents chlorine, bromine or iodine, and

m represents the number 0 or 1.

By lower alkyl is meant, according to the above definitions,straight-chain or branched radicals having 1 to 4 carbon atoms, e.g.,methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec -butyl ortert-butyl. These lower alkyl radicals constitute also the alkyl moietyof an alkoxy radical, or of an alkanoyloxy radical (R,,OCO).

Trifluoromethyl is preferred as halogenalkyl; but methyl or ethylradicals monoor polysubstituted by chlorine and/or fluorine are alsosuitable. By halogen, denoted by R, and/or R are meant, independently ofeach other. fluorine, chlorine, bromine and/or iodine atoms. A phenylradical R, can be monoor polysubstituted by lower alkyl, lower alkoxy orhalogenalkyl, and/or by halogen such as fluorine, chlorine, bromine oriodine.

The halogenethyl esters of aromatic carboxylic acids of formula I areproduced by the reaction of a carboxylic acid derivative of formula ll:

with a compound of formula III:

Z CH CH X ion, or the equivalent of an alkaline-earth metal cation.

It is advantageous if the reaction is performed in the presence of asolvent or diluent inert to the reactants; suitable solvents or diluentsfor this purpose are, e.g., hydrocarbons such as benzene, toluene orxylenes, halogenated hydrocarbons such as chlorobenzene, methylenechloride, ethylene chloride, chloroform, carbon tetrachloride,N,N-dialkylated amides such as dimethylformamide, also ethers andethereal compounds such as dialkyl ether, dioxane, tetrahydrofuran, or,in the case where Y and Z each represent OH, the correspondinghalogenated ethanol. lf Y=Z=OH, or if one of the two symbols representsOH and the other halogen, then the process can be carried out in thepresence of an anhydrous acid or base. Suitable acids are, e.g., thefollowing: hydrohalic acids, sulphuric acid, etc.,v and suitable basesare, e.g., inorganic bases such as alkali metal hydroxides andalkaline-earth metal hydroxides 0r -oxides; and organic bases such astertiary amines.

boxylic acid halide, preferably the chloride or bromide,

is reacted, as the carboxylic acid derivative of formula ll, with a2-halogenethanol (X-CH -CH OH) in the.

presence of a solvent, preferably benzene.

Halogenethyl esters of aromatic carboxylic acids of formula I affect, ina varying manner, the growth of parts of plants above and below thesoil; the compounds have a low toxicity towards warm-blooded animals.The activesubstances cause no morphological changes or damage whichwould result in the withering of the plant. Their action is differentfrom that of a herbicidal active substance and from that of afertiliser. The new compounds affect the germination power and thevegetative plant growth, and promote blossom formation, fruit ripeningand the formation of abscission layers.

By virtue of their effectiveness, the halogenethyl esters of specialimportance are those corresponding to formula IV:

The symbols R A, m and X in this formula have the meanings defined underformula I. Compounds having a particularly gentle effect on plantmetabolism are those compounds of formula I wherein X iodine. Theinvention relates also to these new compounds of formula la:

wherein R R R A and m have the meanings given for formula I, as well asto. the process for their production by the method given for formula I,and also to agents affecting plant metabolism which contain thesecompounds of formula la as active substances.

Compounds particularly suitable for the promotion of fruit and leafabscission are compounds of formula V: I

wherein R represents hydrogen, halogen, trifiuoromethyl,

acetoxy or lower alkyl, and

m represents the number or 1.

2'-Fluoroethyl esters of aromatic carboxylic acids are known from theliterature as insecticidal and acaricidal active substances (cp. theGerman Offenlegungsschrift No. 1,808,938). The compounds are phytotoxicand have a high toxicity towards warm-blooded animals.

The following example serves to illustrate the process according to theinvention. The table following the example contains further halogenethylesters of aromatic carboxylic acids of formula I, which were obtained inthe manner described in the said example. The temperatures are expressedin degrees Centigrade, and the pressure in Torr (1 Torr 1 mm Hg).

Example 1 An amount of g of 3-acetoxybenzoyl chloride is dissolved in200 ml of benzene, and 17.5 g of iodoethanol added. An addition issubsequently made dropwise at 15 with cooling and vigorous stirring, ofl2 g of triethylamine; the organic phase is dried over sodium sulphate,and the solvent distilled off. The oily residue is distilled inhighvacuum. 3-Acetoxybenzoic acid-(2-iodoethyl)-ester passes over at l-l53/0.05 Torr.

Compounds Physical data 3acetoxybenzoic M.P 49-52acid-(2'bromoethyl)-ester 3-acetoxybenzoic M.P 52-54acid-(2-chloroethyl)-ester benzoic acid-(2-iodoethy1)-ester B.P. 87/0.023-chlorobenzoic acid-(2-iodoethyl)-ester B.P. 95/0.0l5 3-bromobenzoicacid-(2iodoethyl)-ester n 1.6050 3-trifluoromethylbenzoic B.P. 85/0.02acid-(2-iodoethyl)-ester 3-methylbenzoic acid'(2-iodoethyl)-ester B.P.96/0.0l 3-methoxybenzoic acid-(2-iodoethyl)-ester n 1.57303.5-dimethoxybenzoic n 1.5317 ucid-(2'-iodoethyl)-ester3.4-dimethylbenzoic u 1.5710 acid-(2'-iodoethyl)-ester 4-methoxybenzoicacid-(2'-iodoethyl)-ester B.P. l38/0.03 3.4-dimethoxybenz0ic M.P 75-77acid-(2'-iodoethyl)-ester cinnamic acid-(2'-iodoethyl)-ester n 1,61643,5-dimethoxybenzoic M.P 52 acid-(2'-chlor'oethyl)-ester 3,S-dimethoxybenzoic n 1.5406 acid-(2'-bromoethyl)-ester 3-fluorobenzoicacidJI-iodoethyl)-ester B.P 98/0.035 3-chlorobenzoicacid-(2'-chl0roethyl)-ester B.P 147ll0 3-chlorobenzoicacid-(2'-bmmoethyl)-ester B.P l58/l() 3-bromobenzoicacid-(2'-chloroethyl)-ester B.P l/l0 3-hromobenzoic acid(2'-bromoethyl)-ester B.P l73/l0 3-trifluoromethylbenzoic B.P 73/0.03acid-(2'-chloroethyl)-ester 3-trifluoromethylbenzoic B.P 82/0.03acid-(2'-brom oethyl)-ester 3-methylbenzoic acid-(2'-chloroethyl)-esterB.P l7'5/10 3-methylhe'nzoic acid-(2'-bromoethyl)-ester B.P 151/103-nitrobenzoic acid-(2-iodoethyl)-ester B.P l35/0.023 3-nitroben2oicacid-(2'-bromoethyl)-ester B.P l25/0.025 3-nitrobenzoicacid-(2-chloroethyl)-ester B.P l30/0.03 3.4-dichlorobenzoic M.P 52-54acid-(2'-iodoethyl)-ester 3,4-dichlorobenzoic M.P 42-44 acid-(2'-bromoethyl )-ester B-(m-chlorobenzoyloxy)-benzoic oil The activesubstances of formula I promote, in particular, the formation ofabscission layers between stalk and fruit stems. Consequently, fruit ofevery kind, such as, e.g., citrus fruits, stone fruit, berries, grapevines, pomaceous or oil fruits, can be picked without any greatapplication of force, either by hand or with machines developed for the.purpose. Damage to the foliage and branches of the tree or bush usuallyoccurring on gathering of the crop as a result of the violent shak-' ingof the trees or bushes, or the'tearing off of the fruit, is largelyavoided.

The extent and the'nature of the action are dependent on the mostdiverse factors, depending on the variety of the plant; they aredependent, in particular, on the applied concentration, and on the timeof application with regard to the stage of development of the plant andof the fruit. Thus, for example, plants of which the fruit is processedor sold will be treated immediately after blossoming, or at a suitablepoint of time before the gathering of the crop. The active substancesare preferably applied in the form of liquid agents to parts of plantsabove the soil, into the soil, or onto the surface of the soil.Application to parts of the plants above the soil is preferred, forwhich application solutions or aqueous dispersions are best suited.

The following tests show the action of the new compounds as abscissionagents.

Example 2 Segments of bean leaves of the variety Tempo or their stemswere immersed in solutions containing 10 and 20 ppm of active substance,respectively. In the case of each active substance, 8 leaf segments ortheir stems were left for 5 days under controlled conditions in theactive substance solution. The number of occurred abscissions wasafterwards determined.

Evaluation: 1 no abscission 2 abscission on 2 segments 3 abscission on 4segments 4 abscission on 6 segments 5 abscission 0n 8 segments-Continued Active substance ppm 20 ppm ester 3-acetoxyhenzoicaeid-(2-iodoethyl)- ester Example 3 I On orange trees of the mentionedvariety, individual branches carrying at least -20 ripe oranges weresprayed with an active substance concentration of 0.4 percent and of 0.2percent. The picking force required in the case of 10 identicallytreated oranges was measured 7 days after applicatiomwith the aid of aspring balance, and the mean value ofthe' 10 measurements calculated [W.C. Wilson and C. H. Hendershott, Proc. Am. Soc. Hort. Science90,'l23-l29 (1967)].

The active substances of formula I produced in this test the percentagereductions in picking force, com,- pared with values obtained withuntreated trees, listed in the following table:

Active substance Concen- Reduction Vari Herbicidal agents according tothe invention are produced in a manner known per se by the intimatemixing and grinding of active substances with'suitable carriers,optionally with the addition of dispersing agents or solvents which areinert to the active substances. The active substances can be obtainedand used in thefollowing forms:

solid preparations: dusts, scattering agents, granulates, (coatedgranulates, impregnated granulates and homogeneous granulates);

water-dispersibleconcentrates of the active substance: wettable powders,pastes, emulsions; liquid preparations: solutions.

The solid preparations (dusts, scattering agents, granulates) areproduced by the mixing of the active substances with solid carriers.Suitable carriers are, e.g., kaolin, talcum, bole, loess, chalk,limestone, ground limestone, Attaclay, dolomite, diatomaceous earth,precipitated silicic acid, alkaline-earth silicates, sodium andpotassium aluminium silicates (feldspar and mica), calcium and magnesiumsulphates, magnesium oxide, ground synthetic materials, fertilisers suchas ammonium sulphate, ammonium phosphate, ammonium nitrate, urea, groundvegetable products such as bran, bark dust, sawdust, ground nutshells,cellulose powder, residues of. plant extractions, active charcoal, etc.,alone or in admixture with each other.

The particle size of the carriers is for dusts advantageously up toabout 0.1 mm; for scattering'agents from about 0.075 mm to 0.2 mm; andfor granulates 0.2mm or coarser.

The concentrations 'of active substance in the solid preparation formsare from 0.5 to percent.

To these mixtures may also be added additives stabilising the activesubstance, and/or non-ionic, anionactive, and cation-active substances,which, for example, improve the adhesiveness of the active substances onplants and on parts of plants (adhesives and agglutinants), and/orensure a better wettability (wetting agents) and dispersibility(dispersing agents). Suitable adhesives are, for example, the following:olein/lime mixture, cellulose derivatives (methyl cellulose,carboxymethyl cellulose), hydroxyethylene glycol ethers of monoalkyl anddialkyl phenols having 5 to 15 ethylene oxide radicals per molecule and8 to 9 carbon atoms in the alkyl radical, ligninsulphonic acids, theiralkali metal and alkaline-earth metal salts, polyethylene glycol ethers(carbowaxes), fatty alcohol polyeth ylene glycol ethers having 5 to 20ethylene oxide radicals per molecule and 8 to 18 carbon atoms in thefatty alcohol moiety, condensation products of ethylene oxide, propyleneoxide, polyvinyl pyrrolidones, polyvinyl alcohols, condensation productsof urea and formaldehyde, as well as latex products.

Water-dispersible concentrates of active substance, -i.e., wettablepowders, pastes and emulsionconcentrates, are agents which can-bediluted with water to obtain any desired concentration. They'consist ofactive substance, carrier, optionally additives which stabilise theactive substance, surface-active substances,

and anti-foam agents and, optionally, solvents. The

concentration of active substance in these agents is 5 to 80 percent.

The wettable powders and the pastes are obtained by the mixing andgrinding of the active substances with dispersing agents and pulverulentcarriers, in suitable devices, until homogeneity is attained. Suitablecarriers are, 'e.g.', thosepreviously mentioned in the case of solidpreparations. It is advantageous in some cases to use mixtures ofdifferent carriers. As dispersing agents itis possible to use, e. g.,:condensation products of sulphonated naphthalene and sulphonatednaphthalene derivatives with formaldehyde, condensation products ofnaphthalene or of naphthalenesulphonicacids with phenol andformaldehyde, as well as alkali, ammonium and alkaline-earth metal saltsof ligninsulphonic acid, also alkylaryl sulphonates, alkali metal saltsand alkaline-earth metal salts of dibutyl naphthalenesulphonic acid,fatty alcohol sulphates such as salts of sulphated hexadecanols,heptadecanols, octadecanols, and salts of sulphated fatty alcohol glycolether, the sodium salt of oleyl' methyl tauride, ditertiary acetyleneglycols, dialkyl dilauryl ammonium chloride, and fatty acid alkalimetaland alkaline-earth metal salts.

Suitable anti-foam agents are, for example, silicones.

The active substances are so mixed, ground, sieved and strained with theabove mentioned additives that the solid constituent in the caseofwettable powders has a particle size not exceeding 0.02 to 0.04 mm, andin the case of pastes not exceeding 0.03 mm. For the preparation ofemulsion concentrates and pastes, dispersing agents are used such asthose mentioned in the preceding paragraphs, organic solvents, andwater. Suitable solvents are, e.g., the following: alcohols, benzene,xylenes, toluene, dimethylsulphoxide, N,N- dialkylated amides, N-oxidesof amines, particularly trialkylamines, and mineral oil fractionsboiling in the range of 120 to 350. The solvents must be practicallyodourless, non-phytotoxic, inert to the active substances, and notreadily inflammable.

Furthermore, the agents according to the invention can be applied in theform of solutions. For this purpose the active substance (or severalactive substances) is (or are) dissolved in suitable organic solvents,mixtures of solvents, water, or mixtures of organic solvents with water.It is possible to use as organic solvents: aliphatic and aromatichydrocarbons, their chlorinated derivatives, alkylnaphthalenes, mineraloils on their own or in admixture with each other. The solutions are tocontain the active substances in a concentration of from 1 to percent.These solutions can be applied with the aid of a propellent gas (asspray), or by means of special sprayers (such as aerosol).

Other biocidal active substances or agents may be added to the describedagents according to the invention. For the. supplementing or broadeningof their sphere of action, the new agents can also contain, in additionto the stated compounds of the general formula I, e.g., insecticides,herbicides, fungicides, bactericides, fungistatics, bacteriostatics ornematocides. The agents according to the invention can also containfertilisers, trace elements, etc..

Preparations of the new active substances are described in thefollowing. The term parts denotes parts by weight.

Wettable powders The following constituents are used for the preparationof(a) a 50 percent, (b) a percent and (c) a 10 percent Wettable powder:

naphthalenesulphonic acid/formaldehyde condensate,

0.5 part of carboxymethyl cellulose, 5 parts of neutralpotassium-aluminium-silicate, 62 parts of kaolin; (c) 10 parts of3-acct0xyben2oic acid-(2'-iodoethyl)-ester, 3 parts of a mixture of thesodium salts of saturated fatty alcohol sulphates, 5 parts ofnaphthalenesulphonic acid/formaldehyde condensate, 82 parts of kaolin.

The active substances are intimately mixed, in suitable mixers, with theadditives; and the mixture is then ground by,means of suitable mills androllers. Wettable powders are obtained which can be diluted with waterto obtain suspensions of any desired concentration.

Emulsion concentrate The following constituents are mixed together forthe preparation of a 25 percent emulsion concentrate:

(a) 25 parts of 3-bromohenzoic acid-(2'-iodoethyl)-ester,

parts of a mixture of nonylphenolpolyoxyethylene andcalcium-dodecylbenzene sulfonate,

parts of xylene.

wherein R is selected from chloro, bromo, fluoro, trifluoromethyl andmethyl radicals; and R is selected from hydrogen, chloro when R, ischloro, and methyl when R, is methyl. i

2. Phenylacetic acid-(2'-iodoethyl)-ester.

2. Phenylacetic acid-(2''-iodoethyl)-ester.